Intrinsic (assumed) and observed spectra for VHE transient events with specific spectral indices (Γ) and cutoff (E_c) for the isotropic energy erg in the 0.2–1 TeV band and redshift of 0.1. The observed spectra are corrected for the EBL attenuation following the prescription of Domínguez et al. (2011). The dot-dashed and solid lines represent the intrinsic and the EBL-attenuated observed spectra, respectively. The shapes of the observed spectra with respect to the intrinsic spectra differ more for harder spectra (extending to higher energy) than the softer ones due to the greater EBL absorption.